Shanghai: Michael Phelps eased his world championships heartache with a 100m butterfly win Saturday as 16-year-old Missy "Missile" Franklin exploded onto the scene with another two gold medals in Shanghai.
Drug-row Brazilian Cesar Cielo earned his second sprint title and Olympic champion Rebecca Adlington broke Britain`s gold medal duck in the women`s 800m, as Franklin helped the United States win their first 4x100m medley in more than a decade.
Phelps, the world and Olympic champion and world record-holder, was third halfway through the 100m butterfly but he swept through the field to win in 50.71sec, ahead of Poland`s Konrad Czerniak and America`s Tyler McGill.
With nemesis Ryan Lochte watching from the stands, Phelps extended his record number of world titles to 25, including three in Shanghai, alongside two silver medals and one bronze.
"I`m not in the right shape physically. I want to be faster. It`s a tough race," Phelps said.
"Sometimes I need to judge what I can do better. I need definitely to push in the first 50 metres. I`ll work on my next game. I`ll watch some races and think about how I can be faster."
Phelps returned to China looking for a possible seven golds, to follow his eight from the 2008 Olympics, but he was beaten by Lochte in the 200m freestyle and again in the 200m individual medley, where his team-mate set a world record.
Phelps now faces the challenge of returning to peak condition for his swansong at next year`s London Olympics, after acknowledging he has neglected training and spent too much time playing golf following the Beijing Games.
The United States also enjoyed yet more success through teenager Franklin, who claimed her second individual title and then anchored the medley victory to make it five medals overall.
Franklin, one of the leading stars of Shanghai, was never behind in the 200m backstroke and she won it convincingly in 2min 5.10sec ahead of Australia`s Belinda Hocking and Sharon van Rouwendaal of the Netherlands.
And the teenager was reliable again in the medley, as the United States held off hosts China and Australia to claim their first world title since 1998.
"It`s been such an incredible meet," said Franklin. "Everything was run perfectly -- the pool was incredible. the crowd were so energetic and honestly, I couldn`t ask for anything better. I`m so thrilled right now."
In other races, Dutch swimmer Inge Dekker upset a field including the world record-holder and defending champion to win the women`s 50m butterfly and claim her first individual world title.
And in the women`s 800m, Britain`s Adlington timed her final burst to perfection as she overtook front-runner Lotte Friis in the closing stages to win it in 8min 17.51sec, with America`s Kate Ziegler third.
Earlier, the controversial Cielo successfully defended his 50m freestyle world title as the sport`s chiefs criticised doping rules after a case involving the Brazilian.
The Olympic champion and world record-holder`s victory never looked in doubt as he surged down the Sea Crown stadium pool to touch in 21.52sec ahead of Italy`s Luca Dotto and French swimmer Alain Bernard.
"It`s been a crazy week, and crazy situation," admitted Cielo, who welled up in tears on the victory podium.
"For next year`s Olympics, I must be a little bit faster. There is a little room to improve. Today I just focused on the race, thought about the race. I am very, very happy."
Cielo has been a contentious figure in Shanghai after escaping suspension on the eve of the championships despite testing positive for a banned diuretic earlier this year.
In an interview with AFP, FINA executive director Cornel Marculescu criticised World Anti-Doping Authority (WADA) rules and said athletes` anger over the case was understandable.
Some swimmers have expressed unhappiness at the ruling and Kenya`s Jason Dunford gave the "thumbs-down" gesture after Cielo`s earlier victory in the 50m butterfly.
The swimming body has now approved a pilot project to create "biological passports" by storing the results of blood tests to detect suspicious variations over time.